Process of making metal caps.



PROCESS 0F MA METAL CAPS.

IIIIIIIIIIIIIIIII 0T.26, 1910.

I. A "@vcafn md/M www UNITED STM-WENT OFFICE.

OSCAEAZERK, F CLEVELAND, OHIO, ASSIGNOR TO THE ZERK MANUFACTURINGCOMPANY, OF CLEVELAND, OHIO, A .CORPORATION OF OHIO.

I To all lwhom t may concern.'

PaocEss or MAKING METAL cArs.

' Specification of LettersiPatent.

Be it known that I, OSCAR giving to t-he exterior of metal caps a suit-`my treatment.

able gripping surface, and the process 'con-- slsts of certain stepsby'which the cap is held and breached without liability of'tear* ing, so'that a thin metal cap may be given The drawing shows,I suitable dieslfo-r broaching the capuand thereby illustrates my process.

In the'drawings, Figure v1 is a central `sect-ion through the `male andfemale die 'and a cap in position to be broached; Fig. 2 is-a crosssection of the female die; Fig. 3 `is a cross section of the male die;Fig. 4 is -a perspective view of the blank cap shown in vertical sectioninl Fig..1; Fig. .5 isa pern spective' of the cap complete; Fig. 6- isa' cross section ofthe cap completed, and'Fig.- 7 is a cross section ofa completed cap zhav ing a modified form of exterior grippingv surface.

As shown in the drawings, 10 represents the male die, which-is'shown asa cylindrif cal member having a reduced cylindrical portion 11 on thesame axis, an abrupt an- `nularishoulder 12 connecting the twocylindrical surfaces. The female die is indicated by 15.- AItis an'annular member having a- .fluted interior providedby suitable parallelribs lfaboutits interior surface, which ribs are parallel with the axisofthe open-- ing. .The smallest diameter of the o ening,`that is thedistance betwee`nl the acesof ribs which are diametrically opposite, `is

preferably slightly greater than the dialneter of the male die. lTheface of the annu'-` l'ar portion of the female'die which'comes adjacentto the cap may be chamfered, as-

shown at 18, a sharp cutting edge being thus provided at the beginningof the flutes or'projections. y

1 20, in .the drawing, indicates a thin ymetal ZERi-i, a citizen of theUnited States, residing at Cleveland, in the county of CuyahogaandState.v

cap having a cylindrical wall and an integral top, designated 21. Beforetreatment with my d1es,the exterior of this cap may Patented May28,1912. Application' mea october 26, 1910. serial No. 589,120. i

bejysmooth, and the cylindrical wall of thel cap may be of substantiallythe same thick- An ess or somewhat greater than the top por- -t1on,Accordingly, the blank which I use may be, itself,

stamped from a' disk of sheet metal.

Fig. 1 shows the blank cap 20 on hamale die ready for the female die'/to be forced down thereon to. broach the 'exterior surface. .It will beseen thatthere /is .some space lbetween the extreme' end -of the portion11 of the male die and the -top 21 of the cap, so that the thrustresultingfrorn the broaching actionis taken on the annu- .lar shoulder12 by the cylindrical wall of the cap. This relieves the's'houflder ofthe cap where the top joins the cylindrical wall from any tension, which.might otherwise tear it.A lVith such a cap in such position, the femaledie is simply forced,downward` over the cap, brojaching theisurfacethereof to produce the'cap` as Ashown in Figs.' 5 and An essentialfeature of the process is to holdthe cap7 ortheportion ofthe cap beingbr'oached,'under compression duringthe broaching. .This enables me tooperatewon av thin metal, which might otherwise tear,

and it insures av uniform finished product.

The cap blank shown in Fig. is.adapted' tobe made by stamping a sheetmetald-isk,

in ya manner well understood. vTliisstamping operation naturallythickens thecylin.

dricalwall and, thoughthe disk is thin, there is', accordingly,suflicient metal on the cylindrical wall to provide, not only vfor the'breached exterior of this process,-but for the internal threads whichare afterward turned into the cap, as shown at 24 .in Fig. 5. The ribsof the femaledie which determine the character of the broaching may havefaces of some extent or may come .to a line, so that the'resultinggripping surface on the cap is of the character shown in Figs. 5 and 6,having parallel sided lribs 22, or of the form shown inF ig. 7 ,Wherethe ribs 23 are Vshaped'.

Having thus what I claim is l. The process 4of treating a .metal capdescribed my invention,`

having a top and side Wall consisting of breaching an exterior portionof the Wall f the cap while the metal adjoining such portion is heldunder, compression against a 'support and With pressure off ofthe top.'

2. The process of treating metal capslconsisting of holding a b1ank,having a cylindrical Wall and a top portion, with the base of theWallagainst a support', and breaching the'exterior surfce of the wall bypres- 10 sure direc'ted toward said shoulder.

In testimony whereof, I hereunto aix my I signature in the presence oftwolwitnesses.

y, OSCAR ZERK. Witnesses: l

B. M. A3011,

ALEX. FoRsTnIN.

